Can Assassin Snail and Red-Tail Catfish Live Together?

🔴Not Recommended

Assassin Snail and Red-Tail Catfish are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Assassin Snail

Clea helena

Red-Tail Catfish

Phractocephalus hemioliopterus

🐠Family Group
Assassin Snail
Invertebrates
Red-Tail Catfish
Catfish
Temperament
Assassin Snail
Peaceful (2/10)
Red-Tail Catfish
Aggressive (7/10)
Temperature
✓ Compatible
Assassin Snail
22–28°C
Red-Tail Catfish
20–28°C
pH Range
✓ Compatible
Assassin Snail
7–8
Red-Tail Catfish
6–7.5
Hardness (dGH)
✓ Compatible
Assassin Snail
8–15
Red-Tail Catfish
3–15
Water Type
✓ Compatible
Assassin Snail
Freshwater Only
Red-Tail Catfish
Freshwater Only
Flow Preference
✓ Compatible
Assassin Snail
Low
Red-Tail Catfish
Moderate
Min Tank Volume
Combined: 4560 L
Assassin Snail
10 L
Red-Tail Catfish
3800 L
Swimming Level
Shared: 1 zone
Assassin Snail
Bottom
Red-Tail Catfish
Bottom
🏷️Behavior Tags
Assassin Snail
Nano / Bite-sized (Predation Risk)Snail EaterDigger (Disturbs Substrate)
Red-Tail Catfish
Piscivore (Eats small/nano fish)Plant DestroyerDigger (Disturbs Substrate)Nocturnal

Behaviour & Temperament

Assassin Snail is a peaceful species (2/10), while Red-Tail Catfish is semi-aggressive (7/10). This notable difference means Red-Tail Catfish may occasionally assert dominance over Assassin Snail.

Assassin Snail and Red-Tail Catfish both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Worth noting: Red-Tail Catfish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

Water Parameters

The safe temperature window for both species falls between 22°C and 28°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Assassin Snail and Red-Tail Catfish together, plan for an aquarium of at least 4560 litres with a minimum length of 300 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Frequently Asked Questions

Can Assassin Snail and Red-Tail Catfish live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Assassin Snail and Red-Tail Catfish need?

A minimum of 4560 litres (tank length at least 300 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Assassin Snail and Red-Tail Catfish together?

Keep the aquarium between 22°C and 28°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Assassin Snail or Red-Tail Catfish aggressive?

Assassin Snail is peaceful (2/10) and Red-Tail Catfish is semi-aggressive (7/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Assassin Snail and Red-Tail Catfish need?

Both species overlap in the 7–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Red-Tail Catfish being nocturnal affect compatibility?

Red-Tail Catfish is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Red-Tail Catfish during evening hours.


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